1. Field of the Invention
The present invention relates to bags for medical use made of a flexible synthetic resin, such as bags for clysis, medical fluid, and blood, and also to a method and apparatus for manufacturing such bags. More particularly, the invention relates to the provision of a system or apparatus for continuously executing a series of manufacturing processes from the extrusion molding of a component material for the bag to the final product in which a medical fluid is filled under sterile and dustless conditions.
2. Prior Art
Bags for clysis, medical fluid, blood, and others for medical use have hitherto been manufactured in the following manner, for example:
(1) Two flexible synthetic resin sheets are superposed. The peripheral edges of the sheets are welded together while making outlet devices or mouths for clysis or the like between the ends of the sheets to form a bag for clysis.
(2) A tube made from a flexible synthetic resin is cut to a predetermined size. By making an outlet device for clysis or the like at either one or both ends of the tube, both of the open ends of the tube are welded to make a bag for clysis.
However, since the method involves welding separate sheets or open ends of a tube by making an outlet device or mouth according to these methods, the inner surface of the sheets or the tube (the inner surface of the bag main body) is exposed to the outside air. Hence there is a possibility that during exposure to the outside air, bacteria, fine-grains, fine particles, cut chips of the outlet device or mouth for clysis or the like adhere to the inner surface of the bag main body. This is not desirable from the standpoint of hygiene. Also, after the bag is formed for medical use, a medical fluid or the like is filled in it. As a result, the number of manufacturing process steps is inevitably increased. Also, there is a danger that the medical fluid or the interior of the bag is contaminated when the medical fluid is filled. Furthermore, in the prior art, a comparatively wide area of the sheets or the ends of the tube must be welded. Thus the power consumption during manufacturing of the bag is comparatively large, resulting in a disadvantage economically.